A kind of apocynum fiber-based spunlace nonwoven fabric and its preparation process

Abstract

The application relates to the technical field of mask base cloth, in particular to a water-jet non-woven fabric based on apocynum fiber and a preparation process thereof. Step 1: (1) apocynum fiber is sequentially immersed in a sodium hydroxide solution and an acetic acid solution for treatment; then the apocynum fiber is transferred to a tetramethyldivinyl disilazane solution for pretreatment, washed and dried to obtain pretreated fiber; (2) the pretreated fiber is sequentially subjected to carding and web laying to obtain an intermediate layer base cloth; step 2: the intermediate layer base cloth is first immersed in a light initiator in an equal volume, dried; then the intermediate layer base cloth is transferred to a mixed solution containing an unsaturated monomer for equal volume immersion, then placed in a sealed reactor, irradiated under a nitrogen atmosphere using a UV lamp, washed and dried to obtain an intermediate water absorption layer; step 3: a skin-friendly layer is prepared; an outer layer is prepared; step 4: the intermediate water absorption layer is stacked with the skin-friendly layer and the outer layer, sequentially subjected to pre-jetting and reinforcing jetting, dried, and the water-jet non-woven fabric is obtained.

Description

Technical Field

[0001] This invention relates to the field of mask base fabric technology, specifically to a spunlace nonwoven fabric based on Apocynum venetum fiber and its preparation process. Background Technology

[0002] Common mask substrates mainly include non-woven fabrics, silk, and bio-fibers. Among them, non-woven fabric substrates are mostly made from cotton fibers, viscose fibers, Tencel fibers, etc., through non-adhesive web formation or hydroentangling.

[0003] According to the Compendium of Materia Medica, Apocynum venetum has calming, beautifying, anti-aging, and age spot-removing effects. Using it as a mask base can synergistically enhance the mask's efficacy. However, among various mask bases, Apocynum venetum fiber is not yet used as the main material. This is because, although Apocynum venetum fiber has high strength, it is relatively stiff, has poor water absorption, poor skin adhesion, and low liquid absorption and retention.

[0004] Therefore, solving the above problems and preparing a spunlace nonwoven fabric based on Apocynum venetum fiber is of great value. Summary of the Invention

[0005] The purpose of this invention is to provide a spunlace nonwoven fabric based on Apocynum venetum fiber and its preparation process, so as to solve the problems mentioned in the background art.

[0006] To solve the above-mentioned technical problems, the present invention provides the following technical solution:

[0007] A process for preparing spunlace nonwoven fabric based on Apocynum venetum fiber includes the following steps:

[0008] Step 1: (1) The Apocynum venetum fibers were immersed in sodium hydroxide solution and acetic acid solution in sequence; then they were transferred to tetramethyldivinyldisilazane solution for pretreatment, washed and dried to obtain pretreated fibers; (2) The pretreated fibers were carded and laid in sequence to obtain the intermediate layer base fabric;

[0009] Step 2: First, impregnate the intermediate layer base fabric in a photoinitiator with an equal volume and dry it; then transfer it to a mixed solution containing unsaturated monomers for impregnation with an equal volume, and then place it in a sealed reactor, irradiate it with an ultraviolet lamp under a nitrogen atmosphere, wash and dry it to obtain the intermediate water-absorbing layer;

[0010] Step 3: The skin-friendly layer is obtained by sequentially opening, blending, carding, and web laying of Apocynum venetum tea fiber, viscose fiber, and silk fiber; the outer layer is obtained by sequentially opening, blending, carding, and web laying of Apocynum venetum tea fiber, viscose fiber, and polyacrylonitrile fiber.

[0011] Step 4: Stack the middle absorbent layer and the skin-friendly layer and the outer layer on top of each other, and perform pre-punching, reinforcement punching and drying in sequence to obtain spunlace nonwoven fabric.

[0012] In a more optimized manner, in step 1(1), the specific process is as follows: first, place the Apocynum venetum fiber in a 0.45-0.5M sodium hydroxide solution and immerse it at 70-75°C for 2-3 hours, then transfer it to a 0.5-0.6M acetic acid solution and immerse it at 70-75°C for 0.5-1 hour; then transfer it to a tetramethyldivinyldisilazane solution and pretreat it at 80-85°C for 2-3 hours, wash and dry it to obtain pretreated fiber.

[0013] More optimally, the impregnation ratio of the Apocynum venetum fiber to the sodium hydroxide solution is 1g:100mL; the impregnation ratio of the Apocynum venetum fiber to the acetic acid solution is 1g:100mL; the ratio of the Apocynum venetum fiber to the tetramethyldivinyldisilazane solution is 1g:(18-20g); the raw materials of the tetramethyldivinyldisilazane solution include the following materials: by weight, 4-5 parts of tetramethyldivinyldisilazane, 4-5 parts of dimethyl sulfoxide, and 10-12 parts of toluene.

[0014] More optimally, in step 2, the initiator solution is an ethanol solution of benzophenone with a concentration of 1-2 wt%; the raw materials of the mixed solution include the following materials by weight: 15-18 parts acrylic acid, 7-9 parts acrylamide, 1-2 parts N,N-methylenebisacrylamide, 10-14 parts itaconic acid monomer, 0.5-1 part ferrous sulfate, and 180-200 parts deionized water.

[0015] More preferably, the raw materials of the mixed solution include the following materials by weight: 15-18 parts acrylic acid, 7-9 parts acrylamide, 1-2 parts N,N-methylenebisacrylamide, 6-9 parts itaconic acid monomer, 4-5 parts itaconic acid modified graphene, 0.5-1 parts ferrous sulfate, and 180-200 parts deionized water.

[0016] A more optimized method for preparing the itaconic acid monomer is as follows: itaconic anhydride is added to tetrahydrofuran, and at room temperature, a 1,6-hexanediamine solution is added dropwise with stirring for 20-30 minutes, followed by stirring for 5-10 minutes, and then filtered, washed, and dried to obtain the itaconic acid monomer; wherein the mass ratio of itaconic anhydride to 1,6-hexanediamine in the 1,6-hexanediamine solution is 2:(2-2.3), and the 1,6-hexanediamine solution is a 0.1 g / mL 1,6-hexanediamine-tetrahydrofuran solution.

[0017] A more optimized method for preparing itaconic acid-modified graphene is as follows: graphene oxide is added to an itaconic acid solution, stirred and dispersed for 1-3 hours, heated to 50-60°C, an aminosilane coupling agent is added, the reaction is carried out for 2-4 hours, filtered, washed and dried to obtain itaconic acid-modified graphene; wherein, the mass ratio of itaconic acid to aminosilane coupling agent in the itaconic acid solution is 10:(3-3.5):(1-1.2); the itaconic acid solution is a 3-3.5 wt% itaconic acid-water solution.

[0018] In a more optimized manner, in step 2, the power of the ultraviolet lamp during irradiation is 1-1.2KW and the irradiation distance is 20-30cm; in step 4, during the pre-puncture process, the needle plate is 0.5-0.8mm and the needle spacing is 2-3mm, and during the reinforcement puncture process, the needle plate is 1-1.5mm.

[0019] More preferably, the raw materials of the skin-friendly layer include the following materials: by weight, 38-42 parts of Apocynum venetum tea fiber, 20-25 parts of viscose fiber, and 8-12 parts of silk fiber; the raw materials of the outer layer include the following materials: by weight, 15-20 parts of Apocynum venetum tea fiber, 30-40 parts of viscose fiber, and 10-15 parts of polyacrylonitrile fiber.

[0020] A more optimized method for preparing spunlace nonwoven fabric based on Apocynum venetum fiber is used to prepare spunlace nonwoven fabric.

[0021] (1) In this design, by setting different fibers (e.g., silkworm silk fiber in the skin-friendly layer and polyacrylonitrile fiber in the outer layer) and different fiber contents in the skin-friendly layer and the outer layer, differences in hydrophilicity are created. This allows the spunlace nonwoven fabric to penetrate into the skin-friendly layer through osmotic pressure generated between the outer layer and the skin-friendly layer, using the middle absorbent layer as a medium. In addition, compared to the middle layer being made of Apocynum venetum fiber, the skin-friendly layer and the outer layer are made of Apocynum venetum tea fiber, which has better skin-friendliness and antioxidant properties. When used as the base fabric of the mask, it can improve the stability of the essence and enhance the activity of the mask.

[0022] (2) In the scheme, Apocynum venetum fiber is used as the base fabric material. It is pretreated and then laid into a web to form an intermediate base fabric. Then, it is in-situ copolymerized and grafted to make the highly absorbent copolymer grafted into the base fabric, thereby effectively improving its water absorption and water retention properties.

[0023] In the pretreatment process, the Apocynum venetum fibers are first treated in sodium hydroxide solution and acetic acid solution in sequence to increase surface porosity and active sites, thereby improving the interaction sites between tetramethyldivinyldisilazane and Apocynum venetum fibers. By utilizing the covalent bond between the silazane molecule and the hydroxyl group, it is grafted onto the Apocynum venetum fibers, giving them vinyl groups, thus obtaining pretreated fibers. This results in an intermediate layer base fabric containing carbon-carbon double bonds, which is beneficial for subsequent in-situ grafting of superabsorbent copolymers.

[0024] In the process of in-situ grafting copolymerization of the intermediate layer base fabric, it is first immersed in a photoinitiator of equal volume to uniformly adsorb the photoinitiator, and then transferred to a mixture containing multiple unsaturated monomers. Under the initiation of ultraviolet light, free radical copolymerization and in-situ grafting are carried out to obtain an intermediate water-absorbing layer loaded with highly absorbent polymer, which effectively improves water absorption and water retention.

[0025] The content of the initiator affects the subsequent grafting and cross-linking of the polymer. Excessive initiation of cross-linking will reduce the water absorption capacity, so its content should not be too high.

[0026] In this mixture of unsaturated monomers, itaconic acid monomer was introduced. Itaconic acid monomer is prepared by the reaction of an acid anhydride and an amino group. After the reaction, the itaconic acid monomer contains a carboxyl group and an amino cation (NH3) at both ends. + The graft copolymer contains double bonds, which can participate in free radical polymerization. Furthermore, due to its ionic effect, it expands the internal network of the graft copolymer, thereby enhancing water molecule absorption. Therefore, its introduction further enhances water absorption and retention.

[0027] Furthermore, since the solution involves a subsequent hydroentangling process, the swelling properties of the surface copolymer in the intermediate absorbent layer are detrimental to the hydroentangling reinforcement process, affecting the mechanical properties of the hydroentangled nonwoven fabric after hydroentangling and damaging the surface grafts, leading to a decrease in absorbency. Therefore, the solution uses itaconic acid-modified graphene to partially replace the itaconic acid monomer, improving the toughness of the surface superabsorbent polymer and thus suppressing the performance degradation of the hydroentangled nonwoven fabric caused by hydroentangling reinforcement. Simultaneously, the solution also employs pre-reinforcement and reinforcement steps to further enhance the performance of the hydroentangled nonwoven fabric.

[0028] In addition, the amount of either itaconic acid monomer or itaconic acid-modified graphene introduced into the mixed solution of unsaturated monomers should not be too large, otherwise it will lead to a decrease in the surface polymerization rate, resulting in a low molecular weight of the surface water-absorbing copolymer, which will dissolve and be lost during the subsequent hydroentanglement process. Detailed Implementation

[0029] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0030] In the following examples, the thickness of the skin-friendly layer and the outer layer is 0.8 mm, and the thickness of the intermediate base fabric is 1 mm. Tetramethyldivinyldisilazane (CAS No.: 7691-02-3), itaconic anhydride (CAS No.: 2170-03-8), 1,6-hexanediamine (CAS No.: 124-09-4), itaconic acid (CAS No.: 97-65-4), acrylic acid (CAS No.: 79-10-7), N,N-methylenebisacrylamide (CAS No.: 110-26-9), acrylamide (CAS No.: 79-06-1), benzophenone (C AS No.: 119-61-9), ferrous sulfate (CAS No.: 7720-78-7), graphene oxide (item No.: 180110132754, (Kramar) Shanghai Ziming Reagent Factory); the fineness of the Apocynum venetum fiber is 0.4 tex, and the average length is 20 mm (Hangzhou Youbiao Textile Co., Ltd.), and the fineness of the Apocynum venetum tea fiber is 0.8 tex, and the average length is 38 mm (Xinjiang Lvkang Apocynum venetum Co., Ltd.); the following parts are by weight.

[0031] Example 1: A process for preparing spunlace nonwoven fabric based on Apocynum venetum fiber, comprising the following steps:

[0032] Step 1: (1) Place the Apocynum venetum fiber in a 0.5M sodium hydroxide solution with an impregnation ratio of 1g:100mL and impregnate at 70°C for 3 hours. Then transfer it to a 0.5M acetic acid solution with an impregnation ratio of 1g:100mL and impregnate at 70°C for 1 hour. Then transfer it to a tetramethyldivinyldisilazane solution with a ratio of 1g:20g and pretreat at 80°C for 3 hours. Wash and dry to obtain pretreated fiber. (2) Card the pretreated fiber and lay it into a web to obtain the intermediate layer base fabric. The raw materials of the tetramethyldivinyldisilazane solution include the following materials: by weight, 5 parts tetramethyldivinyldisilazane, 5 parts dimethyl sulfoxide, and 10 parts toluene.

[0033] Step 2: (1) Add 2g of itaconic anhydride to 30mL of tetrahydrofuran. At room temperature, add 0.1g / mL of 1,6-hexanediamine solution (2.2g of 1,6-hexanediamine) dropwise at 400rpm for 30 minutes. Stir for 5 minutes, filter, wash and dry to obtain itaconic acid monomer.

[0034] (2) Graphene oxide was added to a 3 wt% itaconic acid solution, stirred and dispersed for 2 hours, heated to 60°C, and aminosilane coupling agent KH550 was added. The reaction was carried out for 2 hours, filtered, washed and dried to obtain itaconic acid modified graphene. The mass ratio of graphene oxide, itaconic acid and aminosilane coupling agent KH550 in the itaconic acid solution was 10:3:1.

[0035] (3) The intermediate layer base fabric is first immersed in an equal volume of 1.5wt% benzophenone ethanol solution and dried; then it is transferred to a mixed solution containing unsaturated monomers for immersion in an equal volume, and then placed in a sealed reactor and irradiated for 30 minutes at a distance of 30cm using a 1.2KW ultraviolet lamp under a nitrogen atmosphere; washed and dried to obtain the intermediate absorbent layer; wherein, the raw materials of the mixed solution include the following materials: by weight, 16 parts acrylic acid, 8 parts acrylamide, 1.5 parts N,N-methylenebisacrylamide, 8 parts itaconic acid monomer, 4 parts itaconic acid modified graphene, 1 part ferrous sulfate, and 200 parts deionized water;

[0036] Step 3: The skin-friendly layer is obtained by sequentially processing Apocynum venetum tea fiber, viscose fiber, and silkworm silk fiber through opening, blending, carding, and web laying; the outer layer is obtained by sequentially processing Apocynum venetum tea fiber, viscose fiber, and polyacrylonitrile fiber through opening, blending, carding, and web laying; wherein, the raw materials of the skin-friendly layer include the following materials by weight: 40 parts Apocynum venetum tea fiber, 23 parts viscose fiber, and 12 parts silkworm silk fiber; the raw materials of the outer layer include the following materials by weight: 18 parts Apocynum venetum tea fiber, 35 parts viscose fiber, and 12 parts polyacrylonitrile fiber.

[0037] Step 4: Stack the middle absorbent layer, the skin-friendly layer, and the outer layer on top of each other, and perform pre-punching with a needle plate of 0.5 mm and a needle spacing of 2 mm, followed by reinforcement punching with a needle plate of 1.5 mm. Dry the product to obtain the spunlace nonwoven fabric.

[0038] Example 2: A process for preparing spunlace nonwoven fabric based on Apocynum venetum fiber, comprising the following steps:

[0039] Step 1: (1) Place the Apocynum venetum fiber in a 0.5M sodium hydroxide solution with an impregnation ratio of 1g:100mL and impregnate at 70°C for 3 hours. Then transfer it to a 0.5M acetic acid solution with an impregnation ratio of 1g:100mL and impregnate at 70°C for 1 hour. Then transfer it to a tetramethyldivinyldisilazane solution with a ratio of 1g:20g and pretreat at 80°C for 3 hours. Wash and dry to obtain pretreated fiber. (2) Card the pretreated fiber and lay it into a web to obtain the intermediate layer base fabric. The raw materials of the tetramethyldivinyldisilazane solution include the following materials: by weight, 4 parts tetramethyldivinyldisilazane, 4 parts dimethyl sulfoxide, and 12 parts toluene.

[0040] Step 2: (1) Add 2g of itaconic anhydride to 30mL of tetrahydrofuran. At room temperature, add 0.1g / mL of 1,6-hexanediamine solution (2.2g of 1,6-hexanediamine) dropwise at 400rpm for 30 minutes. Stir for 5 minutes, filter, wash and dry to obtain itaconic acid monomer.

[0041] (2) Graphene oxide was added to a 3 wt% itaconic acid solution, stirred and dispersed for 2 hours, heated to 60°C, and aminosilane coupling agent KH550 was added. The reaction was carried out for 2 hours, filtered, washed and dried to obtain itaconic acid modified graphene. The mass ratio of graphene oxide, itaconic acid and aminosilane coupling agent KH550 in the itaconic acid solution was 10:3:1.

[0042] (3) The intermediate layer base fabric is first immersed in an equal volume of 1wt% benzophenone ethanol solution and dried; then it is transferred to a mixed solution containing unsaturated monomers for immersion in an equal volume, and then placed in a sealed reactor under a nitrogen atmosphere and irradiated for 30 minutes using a 1KW ultraviolet lamp at an irradiation distance of 30cm; washed and dried to obtain the intermediate absorbent layer; wherein, the raw materials of the mixed solution include the following materials: by weight, 15 parts acrylic acid, 7 parts acrylamide, 2 parts N,N-methylenebisacrylamide, 9 parts itaconic acid monomer, 4 parts itaconic acid modified graphene, 1 part ferrous sulfate, and 180 parts deionized water;

[0043] Step 3: The skin-friendly layer is obtained by sequentially processing Apocynum venetum tea fiber, viscose fiber, and silkworm silk fiber through opening, blending, carding, and web laying; the outer layer is obtained by sequentially processing Apocynum venetum tea fiber, viscose fiber, and polyacrylonitrile fiber through opening, blending, carding, and web laying; wherein, the raw materials of the skin-friendly layer include the following materials by weight: 40 parts Apocynum venetum tea fiber, 23 parts viscose fiber, and 12 parts silkworm silk fiber; the raw materials of the outer layer include the following materials by weight: 18 parts Apocynum venetum tea fiber, 35 parts viscose fiber, and 12 parts polyacrylonitrile fiber.

[0044] Step 4: Stack the middle absorbent layer, the skin-friendly layer, and the outer layer on top of each other, and perform pre-punching with a needle plate of 0.5 mm and a needle spacing of 2 mm, followed by reinforcement punching with a needle plate of 1.5 mm. Dry the product to obtain the spunlace nonwoven fabric.

[0045] Example 3: A process for preparing spunlace nonwoven fabric based on Apocynum venetum fiber, comprising the following steps:

[0046] Step 1: (1) Place the Apocynum venetum fiber in a 0.5M sodium hydroxide solution with an impregnation ratio of 1g:100mL and impregnate at 70°C for 3 hours. Then transfer it to a 0.5M acetic acid solution with an impregnation ratio of 1g:100mL and impregnate at 70°C for 1 hour. Then transfer it to a tetramethyldivinyldisilazane solution with a ratio of 1g:20g and pretreat at 80°C for 3 hours. Wash and dry to obtain pretreated fiber. (2) Card the pretreated fiber and lay it into a web to obtain the intermediate layer base fabric. The raw materials of the tetramethyldivinyldisilazane solution include the following materials: by weight, 5 parts tetramethyldivinyldisilazane, 5 parts dimethyl sulfoxide, and 10 parts toluene.

[0047] Step 2: (1) Add 2g of itaconic anhydride to 30mL of tetrahydrofuran. At room temperature, add 0.1g / mL of 1,6-hexanediamine solution (2.2g of 1,6-hexanediamine) dropwise at 400rpm for 30 minutes. Stir for 5 minutes, filter, wash and dry to obtain itaconic acid monomer.

[0048] (2) Graphene oxide was added to a 3 wt% itaconic acid solution, stirred and dispersed for 2 hours, heated to 60°C, and aminosilane coupling agent KH550 was added. The reaction was carried out for 2 hours, filtered, washed and dried to obtain itaconic acid modified graphene. The mass ratio of graphene oxide, itaconic acid and aminosilane coupling agent KH550 in the itaconic acid solution was 10:3:1.

[0049] (3) The intermediate layer base fabric is first immersed in an equal volume of 2wt% benzophenone ethanol solution and dried; then transferred to an equal volume of a mixed solution containing unsaturated monomers for immersion, and then placed in a sealed reactor under a nitrogen atmosphere and irradiated for 30 minutes using a 1.2KW ultraviolet lamp at an irradiation distance of 20cm; washed and dried to obtain the intermediate absorbent layer; wherein, the raw materials of the mixed solution include the following materials: by weight, 18 parts acrylic acid, 9 parts acrylamide, 1 part N,N-methylenebisacrylamide, 6 parts itaconic acid monomer, 5 parts itaconic acid modified graphene, 0.5 parts ferrous sulfate, and 200 parts deionized water;

[0050] Step 3: The skin-friendly layer is obtained by sequentially processing Apocynum venetum tea fiber, viscose fiber, and silkworm silk fiber through opening, blending, carding, and web laying; the outer layer is obtained by sequentially processing Apocynum venetum tea fiber, viscose fiber, and polyacrylonitrile fiber through opening, blending, carding, and web laying; wherein, the raw materials of the skin-friendly layer include the following materials by weight: 40 parts Apocynum venetum tea fiber, 23 parts viscose fiber, and 12 parts silkworm silk fiber; the raw materials of the outer layer include the following materials by weight: 18 parts Apocynum venetum tea fiber, 35 parts viscose fiber, and 12 parts polyacrylonitrile fiber.

[0051] Step 4: Stack the middle absorbent layer, the skin-friendly layer, and the outer layer on top of each other, and perform pre-punching with a needle plate of 0.5 mm and a needle spacing of 2 mm, followed by reinforcement punching with a needle plate of 1.5 mm. Dry the product to obtain the spunlace nonwoven fabric.

[0052] Example 4: A process for preparing spunlace nonwoven fabric based on Apocynum venetum fiber, comprising the following steps:

[0053] Step 1: (1) Place the Apocynum venetum fiber in a 0.5M sodium hydroxide solution with an impregnation ratio of 1g:100mL and impregnate at 70°C for 3 hours. Then transfer it to a 0.5M acetic acid solution with an impregnation ratio of 1g:100mL and impregnate at 70°C for 1 hour. Then transfer it to a tetramethyldivinyldisilazane solution with a ratio of 1g:20g and pretreat at 80°C for 3 hours. Wash and dry to obtain pretreated fiber. (2) Card the pretreated fiber and lay it into a web to obtain the intermediate layer base fabric. The raw materials of the tetramethyldivinyldisilazane solution include the following materials: by weight, 5 parts tetramethyldivinyldisilazane, 5 parts dimethyl sulfoxide, and 10 parts toluene.

[0054] Step 2: (1) Add 2g of itaconic anhydride to 30mL of tetrahydrofuran. At room temperature, add 0.1g / mL of 1,6-hexanediamine solution (2.2g of 1,6-hexanediamine) dropwise at 400rpm for 30 minutes. Stir for 5 minutes, filter, wash and dry to obtain itaconic acid monomer.

[0055] (2) Graphene oxide was added to a 3 wt% itaconic acid solution, stirred and dispersed for 2 hours, heated to 60°C, and aminosilane coupling agent KH550 was added. The reaction was carried out for 2 hours, filtered, washed and dried to obtain itaconic acid modified graphene. The mass ratio of graphene oxide, itaconic acid and aminosilane coupling agent KH550 in the itaconic acid solution was 10:3:1.

[0056] (3) The intermediate layer base fabric is first immersed in an equal volume of 1.5wt% benzophenone ethanol solution and dried; then it is transferred to a mixed solution containing unsaturated monomers and immersed in an equal volume, and then placed in a sealed reactor and irradiated for 30 minutes at a distance of 30cm using a 1.2KW ultraviolet lamp under a nitrogen atmosphere; washed and dried to obtain the intermediate absorbent layer; wherein, the raw materials of the mixed solution include the following materials: by weight, 16 parts acrylic acid, 8 parts acrylamide, 1.5 parts N,N-methylenebisacrylamide, 12 parts itaconic acid monomer, 1 part ferrous sulfate, and 200 parts deionized water;

[0057] Step 3: The skin-friendly layer is obtained by sequentially processing Apocynum venetum tea fiber, viscose fiber, and silkworm silk fiber through opening, blending, carding, and web laying; the outer layer is obtained by sequentially processing Apocynum venetum tea fiber, viscose fiber, and polyacrylonitrile fiber through opening, blending, carding, and web laying; wherein, the raw materials of the skin-friendly layer include the following materials by weight: 40 parts Apocynum venetum tea fiber, 23 parts viscose fiber, and 12 parts silkworm silk fiber; the raw materials of the outer layer include the following materials by weight: 18 parts Apocynum venetum tea fiber, 35 parts viscose fiber, and 12 parts polyacrylonitrile fiber.

[0058] Step 4: Stack the middle absorbent layer, the skin-friendly layer, and the outer layer on top of each other, and perform pre-punching with a needle plate of 0.5 mm and a needle spacing of 2 mm, followed by reinforcement punching with a needle plate of 1.5 mm. Dry the product to obtain the spunlace nonwoven fabric.

[0059] Comparative Example 1: No tetramethyldivinyldisilazane pretreatment was performed; all other aspects were the same as in Example 1.

[0060] Step 1: (1) Place the Apocynum venetum fiber in a 0.5M sodium hydroxide solution with an impregnation ratio of 1g:100mL and impregnate at 70℃ for 3 hours. Then transfer it to a 0.5M acetic acid solution with an impregnation ratio of 1g:100mL and impregnate at 70℃ for 1 hour. Wash and dry to obtain pretreated fiber; (2) Card and lay the pretreated fiber sequentially to obtain the intermediate layer base fabric.

[0061] Step 2: (1) Add 2g of itaconic anhydride to 30mL of tetrahydrofuran. At room temperature, add 0.1g / mL of 1,6-hexanediamine solution (2.2g of 1,6-hexanediamine) dropwise at 400rpm for 30 minutes. Stir for 5 minutes, filter, wash and dry to obtain itaconic acid monomer.

[0062] (2) Graphene oxide was added to a 3 wt% itaconic acid solution, stirred and dispersed for 2 hours, heated to 60°C, and aminosilane coupling agent KH550 was added. The reaction was carried out for 2 hours, filtered, washed and dried to obtain itaconic acid modified graphene. The mass ratio of graphene oxide, itaconic acid and aminosilane coupling agent KH550 in the itaconic acid solution was 10:3:1.

[0063] (3) The intermediate layer base fabric is first immersed in an equal volume of 1.5wt% benzophenone ethanol solution and dried; then it is transferred to a mixed solution containing unsaturated monomers for immersion in an equal volume, and then placed in a sealed reactor and irradiated for 30 minutes at a distance of 30cm using a 1.2KW ultraviolet lamp under a nitrogen atmosphere; washed and dried to obtain the intermediate absorbent layer; wherein, the raw materials of the mixed solution include the following materials: by weight, 16 parts acrylic acid, 8 parts acrylamide, 1.5 parts N,N-methylenebisacrylamide, 8 parts itaconic acid monomer, 4 parts itaconic acid modified graphene, 1 part ferrous sulfate, and 200 parts deionized water;

[0064] Step 3: The skin-friendly layer is obtained by sequentially processing Apocynum venetum tea fiber, viscose fiber, and silkworm silk fiber through opening, blending, carding, and web laying; the outer layer is obtained by sequentially processing Apocynum venetum tea fiber, viscose fiber, and polyacrylonitrile fiber through opening, blending, carding, and web laying; wherein, the raw materials of the skin-friendly layer include the following materials by weight: 40 parts Apocynum venetum tea fiber, 23 parts viscose fiber, and 12 parts silkworm silk fiber; the raw materials of the outer layer include the following materials by weight: 18 parts Apocynum venetum tea fiber, 35 parts viscose fiber, and 12 parts polyacrylonitrile fiber.

[0065] Step 4: Stack the middle absorbent layer and the skin-friendly layer and the outer layer on top of each other, and perform pre-punching with a needle plate of 0.5 mm and a needle spacing of 2 mm, and reinforce punching with a needle plate of 1.5 mm. Dry to obtain spunlace nonwoven fabric.

[0066] Comparative Example 2: The initiator concentration was increased to 3 wt%, and the rest was the same as in Example 1;

[0067] Step 1: (1) Place the Apocynum venetum fiber in a 0.5M sodium hydroxide solution with an impregnation ratio of 1g:100mL and impregnate at 70°C for 3 hours. Then transfer it to a 0.5M acetic acid solution with an impregnation ratio of 1g:100mL and impregnate at 70°C for 1 hour. Then transfer it to a tetramethyldivinyldisilazane solution with a ratio of 1g:20g and pretreat at 80°C for 3 hours. Wash and dry to obtain pretreated fiber. (2) Card the pretreated fiber and lay it into a web to obtain the intermediate layer base fabric. The raw materials of the tetramethyldivinyldisilazane solution include the following materials: by weight, 5 parts tetramethyldivinyldisilazane, 5 parts dimethyl sulfoxide, and 10 parts toluene.

[0068] Step 2: (1) Add 2g of itaconic anhydride to 30mL of tetrahydrofuran. At room temperature, add 0.1g / mL of 1,6-hexanediamine solution (2.2g of 1,6-hexanediamine) dropwise at 400rpm for 30 minutes. Stir for 5 minutes, filter, wash and dry to obtain itaconic acid monomer.

[0069] (2) Graphene oxide was added to a 3 wt% itaconic acid solution, stirred and dispersed for 2 hours, heated to 60°C, and aminosilane coupling agent KH550 was added. The reaction was carried out for 2 hours, filtered, washed and dried to obtain itaconic acid modified graphene. The mass ratio of graphene oxide, itaconic acid and aminosilane coupling agent KH550 in the itaconic acid solution was 10:3:1.

[0070] (3) The intermediate layer base fabric is first immersed in an equal volume of 3wt% benzophenone ethanol solution and dried; then transferred to an equal volume of a mixed solution containing unsaturated monomers for immersion, and then placed in a sealed reactor under a nitrogen atmosphere and irradiated for 30 minutes using a 1.2KW ultraviolet lamp at an irradiation distance of 30cm; washed and dried to obtain the intermediate absorbent layer; wherein, the raw materials of the mixed solution include the following materials: by weight, 16 parts acrylic acid, 8 parts acrylamide, 1.5 parts N,N-methylenebisacrylamide, 8 parts itaconic acid monomer, 4 parts itaconic acid modified graphene, 1 part ferrous sulfate, and 200 parts deionized water;

[0071] Step 3: The skin-friendly layer is obtained by sequentially processing Apocynum venetum tea fiber, viscose fiber, and silkworm silk fiber through opening, blending, carding, and web laying; the outer layer is obtained by sequentially processing Apocynum venetum tea fiber, viscose fiber, and polyacrylonitrile fiber through opening, blending, carding, and web laying; wherein, the raw materials of the skin-friendly layer include the following materials by weight: 40 parts Apocynum venetum tea fiber, 23 parts viscose fiber, and 12 parts silkworm silk fiber; the raw materials of the outer layer include the following materials by weight: 18 parts Apocynum venetum tea fiber, 35 parts viscose fiber, and 12 parts polyacrylonitrile fiber.

[0072] Step 4: Stack the middle absorbent layer and the skin-friendly layer and the outer layer on top of each other, and perform pre-punching with a needle plate of 0.5 mm and a needle spacing of 2 mm, and reinforce punching with a needle plate of 1.5 mm. Dry to obtain spunlace nonwoven fabric.

[0073] Comparative Example 3: The content of itaconic acid monomer was increased, and the rest was the same as in Example 1;

[0074] Step 1: (1) Place the Apocynum venetum fiber in a 0.5M sodium hydroxide solution with an impregnation ratio of 1g:100mL and impregnate at 70°C for 3 hours. Then transfer it to a 0.5M acetic acid solution with an impregnation ratio of 1g:100mL and impregnate at 70°C for 1 hour. Then transfer it to a tetramethyldivinyldisilazane solution with a ratio of 1g:20g and pretreat at 80°C for 3 hours. Wash and dry to obtain pretreated fiber. (2) Card the pretreated fiber and lay it into a web to obtain the intermediate layer base fabric. The raw materials of the tetramethyldivinyldisilazane solution include the following materials: by weight, 5 parts tetramethyldivinyldisilazane, 5 parts dimethyl sulfoxide, and 10 parts toluene.

[0075] Step 2: (1) Add 2g of itaconic anhydride to 30mL of tetrahydrofuran. At room temperature, add 0.1g / mL of 1,6-hexanediamine solution (2.2g of 1,6-hexanediamine) dropwise at 400rpm for 30 minutes. Stir for 5 minutes, filter, wash and dry to obtain itaconic acid monomer.

[0076] (2) Graphene oxide was added to a 3 wt% itaconic acid solution, stirred and dispersed for 2 hours, heated to 60°C, and aminosilane coupling agent KH550 was added. The reaction was carried out for 2 hours, filtered, washed and dried to obtain itaconic acid modified graphene. The mass ratio of graphene oxide, itaconic acid and aminosilane coupling agent KH550 in the itaconic acid solution was 10:3:1.

[0077] (3) The intermediate layer base fabric is first immersed in an equal volume of 1.5wt% benzophenone ethanol solution and dried; then it is transferred to a mixed solution containing unsaturated monomers for immersion in an equal volume, and then placed in a sealed reactor and irradiated for 30 minutes at a distance of 30cm using a 1.2KW ultraviolet lamp under a nitrogen atmosphere; washed and dried to obtain the intermediate absorbent layer; wherein, the raw materials of the mixed solution include the following materials: by weight, 16 parts acrylic acid, 8 parts acrylamide, 1.5 parts N,N-methylenebisacrylamide, 16 parts itaconic acid monomer, 4 parts itaconic acid modified graphene, 1 part ferrous sulfate, and 200 parts deionized water;

[0078] Step 3: The skin-friendly layer is obtained by sequentially processing Apocynum venetum tea fiber, viscose fiber, and silkworm silk fiber through opening, blending, carding, and web laying; the outer layer is obtained by sequentially processing Apocynum venetum tea fiber, viscose fiber, and polyacrylonitrile fiber through opening, blending, carding, and web laying; wherein, the raw materials of the skin-friendly layer include the following materials by weight: 40 parts Apocynum venetum tea fiber, 23 parts viscose fiber, and 12 parts silkworm silk fiber; the raw materials of the outer layer include the following materials by weight: 18 parts Apocynum venetum tea fiber, 35 parts viscose fiber, and 12 parts polyacrylonitrile fiber.

[0079] Step 4: Stack the middle absorbent layer, the skin-friendly layer, and the outer layer on top of each other, and perform pre-punching with a needle plate of 0.5 mm and a needle spacing of 2 mm, followed by reinforcement punching with a needle plate of 1.5 mm. Dry the product to obtain the spunlace nonwoven fabric.

[0080] Comparative Example 4: The content of itaconic acid-modified graphene was increased, and the rest was the same as in Example 1;

[0081] Step 1: (1) Place the Apocynum venetum fiber in a 0.5M sodium hydroxide solution with an impregnation ratio of 1g:100mL and impregnate at 70°C for 3 hours. Then transfer it to a 0.5M acetic acid solution with an impregnation ratio of 1g:100mL and impregnate at 70°C for 1 hour. Then transfer it to a tetramethyldivinyldisilazane solution with a ratio of 1g:20g and pretreat at 80°C for 3 hours. Wash and dry to obtain pretreated fiber. (2) Card the pretreated fiber and lay it into a web to obtain the intermediate layer base fabric. The raw materials of the tetramethyldivinyldisilazane solution include the following materials: by weight, 5 parts tetramethyldivinyldisilazane, 5 parts dimethyl sulfoxide, and 10 parts toluene.

[0082] Step 2: (1) Add 2g of itaconic anhydride to 30mL of tetrahydrofuran. At room temperature, add 0.1g / mL of 1,6-hexanediamine solution (2.2g of 1,6-hexanediamine) dropwise at 400rpm for 30 minutes. Stir for 5 minutes, filter, wash and dry to obtain itaconic acid monomer.

[0083] (2) Graphene oxide was added to a 3 wt% itaconic acid solution, stirred and dispersed for 2 hours, heated to 60°C, and aminosilane coupling agent KH550 was added. The reaction was carried out for 2 hours, filtered, washed and dried to obtain itaconic acid modified graphene. The mass ratio of graphene oxide, itaconic acid and aminosilane coupling agent KH550 in the itaconic acid solution was 10:3:1.

[0084] (3) The intermediate layer base fabric is first immersed in an equal volume of 1.5wt% benzophenone ethanol solution and dried; then it is transferred to a mixed solution containing unsaturated monomers for immersion in an equal volume, and then placed in a sealed reactor and irradiated for 30 minutes at a distance of 30cm using a 1.2KW ultraviolet lamp under a nitrogen atmosphere; washed and dried to obtain the intermediate absorbent layer; wherein, the raw materials of the mixed solution include the following materials: by weight, 16 parts acrylic acid, 8 parts acrylamide, 1.5 parts N,N-methylenebisacrylamide, 8 parts itaconic acid monomer, 8 parts itaconic acid modified graphene, 1 part ferrous sulfate, and 200 parts deionized water;

[0085] Step 3: The skin-friendly layer is obtained by sequentially processing Apocynum venetum tea fiber, viscose fiber, and silkworm silk fiber through opening, blending, carding, and web laying; the outer layer is obtained by sequentially processing Apocynum venetum tea fiber, viscose fiber, and polyacrylonitrile fiber through opening, blending, carding, and web laying; wherein, the raw materials of the skin-friendly layer include the following materials by weight: 40 parts Apocynum venetum tea fiber, 23 parts viscose fiber, and 12 parts silkworm silk fiber; the raw materials of the outer layer include the following materials by weight: 18 parts Apocynum venetum tea fiber, 35 parts viscose fiber, and 12 parts polyacrylonitrile fiber.

[0086] Step 4: Stack the middle absorbent layer and the skin-friendly layer and the outer layer on top of each other, and perform pre-punching with a needle plate of 0.5 mm and a needle spacing of 2 mm, and reinforce punching with a needle plate of 1.5 mm. Dry to obtain spunlace nonwoven fabric.

[0087] Experiment: The spunlace nonwoven fabrics prepared in the examples and comparative examples were tested for tensile strength using an electronic tensile testing machine according to Part 3 of GB / T24218.3; a 2cm sample was taken. 2 The sample was boiled in 100℃ boiling water for 10 minutes, the surface moisture was absorbed, and it was weighed. Then it was dried at 60℃ to constant weight, weighed again, and the water holding capacity A was calculated to characterize the liquid absorbency. Similarly, a 2cm sample was taken. 2 The samples were boiled in 100℃ boiling water for 30 minutes, centrifuged at 1500rpm for 15 minutes, surface moisture was removed, and the samples were weighed. They were then dried at 60℃ to constant weight and weighed again. Finally, the water holding capacity B was calculated to characterize the water retention performance. The obtained data are shown below:

[0088] Example 1 1.18 33.6 30.5 Example 2 1.16 33.0 29.1 Example 3 1.13 33.2 29.8 Example 4 1.05 31.6 27.3 Comparative Example 1 1.07 30.5 27.1 Comparative Example 2 1.10 29.9 28.0 Comparative Example 3 1.08 31.4 28.1 Comparative Example 4 1.11 30.9 28.5

[0089] The data in the table above shows that the spunlace nonwoven fabric prepared based on Apocynum venetum fiber in the proposed scheme has good mechanical properties, as well as excellent liquid absorption and retention, making it an excellent substrate suitable for use as a mask base fabric. Data from Example 4 shows that partially replacing itaconic acid monomer with itaconic acid-modified graphene can effectively improve the mechanical properties of the spunlace nonwoven fabric. Data from Comparative Examples 1-4 indicate that in Comparative Example 1, not using tetramethyldivinyldisilazane for pretreatment, increasing the initiator concentration, increasing the amount of itaconic acid monomer introduced, and increasing the amount of itaconic acid-modified graphene introduced all affect the performance of the spunlace nonwoven fabric. This fully demonstrates that the rationally designed intermediate absorbent layer in the proposed scheme solves the technical problems of using Apocynum venetum fiber in nonwoven fabrics and effectively improves the performance of the spunlace nonwoven fabric.

[0090] Finally, it should be noted that the above descriptions are merely preferred embodiments of the present invention and are not intended to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A process for preparing spunlace nonwoven fabric based on Apocynum venetum fiber, characterized in that: The process includes the following: Step 1: (1) Immerse the Apocynum venetum fibers in sodium hydroxide solution and acetic acid solution in sequence; Then, the fiber was transferred to a tetramethyldivinyldisilazane solution for pretreatment, washed and dried to obtain pretreated fiber; (2) the pretreated fiber was sequentially carded and laid into a web to obtain the intermediate layer base fabric; Step 2: First, impregnate the intermediate layer base fabric in a photoinitiator with an equal volume and dry it; then transfer it to a mixed solution containing unsaturated monomers for impregnation with an equal volume, and then place it in a sealed reactor, irradiate it with an ultraviolet lamp under a nitrogen atmosphere, wash and dry it to obtain the intermediate water-absorbing layer; Step 3: The skin-friendly layer is obtained by sequentially opening, blending, carding, and web laying of Apocynum venetum tea fiber, viscose fiber, and silk fiber; the outer layer is obtained by sequentially opening, blending, carding, and web laying of Apocynum venetum tea fiber, viscose fiber, and polyacrylonitrile fiber. Step 4: Stack the middle absorbent layer and the skin-friendly layer and the outer layer on top of each other, and perform pre-punching, reinforcement punching and drying in sequence to obtain spunlace nonwoven fabric.

2. The preparation process of a spunlace nonwoven fabric based on Apocynum venetum fiber according to claim 1, characterized in that: In step 1(1), the specific process is as follows: first, place the Apocynum venetum fiber in a 0.45-0.5M sodium hydroxide solution and immerse it at 70-75°C for 2-3 hours, then transfer it to a 0.5-0.6M acetic acid solution and immerse it at 70-75°C for 0.5-1 hours; then transfer it to a tetramethyldivinyldisilazane solution and pretreat it at 80-85°C for 2-3 hours, wash and dry it to obtain pretreated fiber.

3. The preparation process of a spunlace nonwoven fabric based on Apocynum venetum fiber according to claim 2, characterized in that: The impregnation ratio of the Apocynum venetum fiber to the sodium hydroxide solution is 1g:100mL; the impregnation ratio of the Apocynum venetum fiber to the acetic acid solution is 1g:100mL; the ratio of the Apocynum venetum fiber to the tetramethyldivinyldisilazane solution is 1g:(18-20g); the raw materials of the tetramethyldivinyldisilazane solution include the following materials: by weight, 4-5 parts of tetramethyldivinyldisilazane, 4-5 parts of dimethyl sulfoxide, and 10-12 parts of toluene.

4. The preparation process of a spunlace nonwoven fabric based on Apocynum venetum fiber according to claim 1, characterized in that: In step 2, the initiator solution is an ethanol solution of benzophenone with a concentration of 1-2 wt%; the raw materials of the mixed solution include the following materials by weight: 15-18 parts acrylic acid, 7-9 parts acrylamide, 1-2 parts N,N-methylenebisacrylamide, 10-14 parts itaconic acid monomer, 0.5-1 part ferrous sulfate, and 180-200 parts deionized water.

5. The preparation process of a spunlace nonwoven fabric based on Apocynum venetum fiber according to claim 1, characterized in that: The raw materials of the mixed solution include the following materials by weight: 15-18 parts acrylic acid, 7-9 parts acrylamide, 1-2 parts N,N-methylenebisacrylamide, 6-9 parts itaconic acid monomer, 4-5 parts itaconic acid modified graphene, 0.5-1 parts ferrous sulfate, and 180-200 parts deionized water.

6. The preparation process of a spunlace nonwoven fabric based on Apocynum venetum fiber according to claim 4, characterized in that: The preparation method of the itaconic acid monomer is as follows: itaconic anhydride is added to tetrahydrofuran, and 1,6-hexanediamine solution is added dropwise with stirring at room temperature for 20-30 minutes. After stirring for 5-10 minutes, the mixture is filtered, washed, and dried to obtain the itaconic acid monomer. The mass ratio of itaconic anhydride to 1,6-hexanediamine in the 1,6-hexanediamine solution is 2:(2-2.3), and the 1,6-hexanediamine solution is a 0.1 g / mL 1,6-hexanediamine-tetrahydrofuran solution.

7. The preparation process of a spunlace nonwoven fabric based on Apocynum venetum fiber according to claim 5, characterized in that: The preparation method of itaconic acid modified graphene is as follows: graphene oxide is added to itaconic acid solution, stirred and dispersed for 1-3 hours, heated to 50-60℃, aminosilane coupling agent is added, reacted for 2-4 hours, filtered, washed and dried to obtain itaconic acid modified graphene; wherein, the mass ratio of itaconic acid to aminosilane coupling agent in graphene oxide solution is 10:(3-3.5):(1-1.2); the itaconic acid solution is 3-3.5 wt% itaconic acid-water solution.

8. The preparation process of a spunlace nonwoven fabric based on Apocynum venetum fiber according to claim 4, characterized in that: In step 2, during the ultraviolet lamp irradiation process, the power is 1-1.2KW and the irradiation distance is 20-30cm; in step 4, during the pre-puncture process, the needle plate is 0.5-0.8mm and the needle spacing is 2-3mm; during the reinforcement puncture process, the needle plate is 1-1.5mm.

9. The preparation process of a spunlace nonwoven fabric based on Apocynum venetum fiber according to claim 1, characterized in that: The raw materials of the skin-friendly layer include the following: by weight, 38-42 parts of Apocynum venetum tea fiber, 20-25 parts of viscose fiber, and 8-12 parts of silkworm silk fiber; the raw materials of the outer layer include the following: by weight, 15-20 parts of Apocynum venetum tea fiber, 30-40 parts of viscose fiber, and 10-15 parts of polyacrylonitrile fiber.

10. A spunlace nonwoven fabric prepared according to any one of claims 1 to 9 using a process for preparing a spunlace nonwoven fabric based on Apocynum venetum fiber.